An endoscopic surgery using a rigid endoscope such as a laparoscope or a thoracoscope is a low-invasive operation for performing a test or treatment procedure without opening the patient's abdomen. In an endoscopic surgery, a medical device such as forceps and an endoscope are separately introduced into a body cavity of the patient. The operator then sets the distal end portion of the medical device inserted into the body cavity such that it is imaged in the observation field of view of the endoscope and conducts the procedure tasks while observing the state of the area being treated with the medical device through the endoscope. In an endoscopic surgery, medical devices and an endoscope are introduced into a body cavity through four or five pipes (tubular members, so-called trocars) inserted into the body wall (for example, abdominal wall) such as in the patient's abdomen.
When cutting open or suturing an organ, the operator inserts the endoscope and medical devices into separate trocars. Trocars are disposed in advance at positions suited for the operation to be performed, and for reducing the patient's burden, they are never changed to different positions once they are set. Thus, the manipulation of the endoscope and medical devices is limited by the positions of trocars and such devices can interfere with each other depending on the circumstance of the operation.
A single-port laparoscopic surgery is a method in which a single small hole of about 15 mm is made in the patient's navel through which forceps (a medical device) and an endoscope camera are inserted for resecting and removing the gallbladder, for example. In a single-port laparoscopic surgery, a surgeon (a camera assistant) manipulates the endoscope camera to capture the image of the inside of the patient's body, which is displayed on a camera monitor outside the body. A surgeon (the operator) different from the camera assistant conducts the operation while watching the camera monitor by manipulating two pairs of forceps respectively held in his right and left hands. The endoscope camera captures the affected area of the patient from above the forceps.
Because a single-port laparoscopic surgery leaves a scar only in the navel, it adds to the advantages of endoscopic surgeries over open procedures as follows:
(1) Being cosmetically favorable due to a less noticeable scar.
(2) Less pain after the operation.
(3) Shorter hospital stay (two or three days) than conventional operation methods because of quick recovery, thus helping reducing health care costs.
(4) Capable of being safely performed on physically weak patients (elderly people) because of low burden on the body.
On the other hand, the conventional single-port laparoscopic surgeries have the following problems:
(1) Contact and interference between persons and surgery devices outside the patient's body.
(2) Contact between the operator and the camera assistant.
(3) Contact between forceps and the endoscope camera.
In order to overcome these problems of endoscopic and single-port laparoscopic surgeries, the distal end portion of an endoscope device is required to have a curvable structure for taking images of the area being treated in the abdominal cavity. Such a curving structure is typically formed from wires for manipulating multiple joints by pulling them. Another type of known curving structure produces a bending motion by supplying fluid to its interior and inflating an elastic pressurizing chamber with the pressure of the fluid (PTLs 1 and 2).
PTL 1 discloses a configuration of a flexible tube having a curving portion including three elastic pressurizing chambers per joint, where the pressurizing chambers and multiple pressurizing tubes as many as the number of pressurizing chambers are disposed on the outer periphery of the flexible tube. PTL 1 discloses embodiments with mesh tubes used as pressurizing tubes for prevention of stretching or fibrous material wrapped around the pressurizing tubes.
PTL 2, for example, discloses a configuration of a flexible tube having a curving portion with three elastic pressurizing chambers per joint, where the pressurizing chambers and multiple non-stretching pressurizing tubes as many as the number of pressurizing chambers are disposed in the wall of the flexible tube.